♦ KNOWLEDGE ♦ 



[July 4, 1884. 



first some expense was incurred, all this was finally repaid, 

 and, at the end of six years, there remained a nett profit 

 of 100,000 florins " after expenses of every kind, salaries, 

 wages, repairs, ic, had been deducted." 



I must not dwell upon his devices for gradually in- 

 veigling the lazy creatures into habits of industry, for he 

 understood human nature too well to adopt the gaoler's 

 theory, which assumes that every able-bodied man can do 

 a day's work daily, in spite of previous habits. Rumford's 

 patients became industrious ultimately, but were not made 

 so at once. 



This development of industry was one of the elements of 

 financial and moral success, and the next in importance 

 was the economy of the commissariat, which depended on 

 Rumford's skilful cookery of the cheapest viands, rendering 

 them digestible, nutritious, and palatable. Had he adopted 

 the dietary of an English workhouse or an English prison, 

 his financial success would have been impossible, and his 

 patients would have been no better fed, nor better able to 

 work. 



The staple food was what he calls a " soup," but I find, 

 on following out his instructions for making it, that I 

 obtain a porridge rather than a soup. He made many 

 experiments, and says : " I constantly found that the rich- 

 ness or quality of a soup depended more upon a proper 

 choice of the ingredients, and a proper management of the 

 fire in the combination of these ingredients, than upon the 

 quantity of solid nutritious matter employed ; — much more 

 upon the art and .skill of the cook than upon the sum laid 

 out in the market." 



Our vegetarian friends will be interested in learning 

 that at first he used meat in the soup provided for the 

 beggars, but gradually omitted it, and the change was un- 

 noticed by those who ate, and no difierence was observable 

 as regards its nutritive value. 



In 1790 little, or rather nothing, was known of the che- 

 mistry of food. Oxygen had been discovered only sixteen 

 years before, and chemical analysis, as now understood, was 

 an unknown art. In spite of this, Rumford selected as the 

 basis of his soup just that proximate element which we 

 now know to contain, bulk for bulk, more nutritive matter 

 ■than any other that exists either in the animal or vege- 

 table kingdom, viz., casein. He not only selected this, 

 but he combined it with those other constituents of food 

 which our highest refinements of modern practical, che- 

 mistry, and physiology have proved to be exactly what are 

 reqxiired to supplement the casein and constitute a com- 

 plete dietary. By selecting the cheapest form of casein 

 and the cheapest sources of the other constituents, he 

 succeeded in supplying the beggars with good hot dinners 

 daily at the cost of one halfpenny each. The cost of the 

 mess for the Bavarian soldiers under his command was rather 

 jnore, viz., twopence daily, three farthings of this being 

 devoted to pure luxuries, such as beer, ic. The details of 

 the means by which he achieved these notable results will 

 be stated in my next. 



Apropos of the great enthusiasm at present existing on the sub- 

 ject of photography, and the number of distinguished amateurs 

 who practise the art, it may interest our readers to know that 

 among them may be included H.E.H. Due de Chartres, who has 

 just favoured Messrs. Watson & Sons, of 313, High Holborn, with 

 an order for complete outfits to take pictures up to 18 by 16 inches. 



The members of the Harleian Society have received during the 

 week the " Visitation of London, 1633-4," Vol. II., edited by Dr. 

 J. J. Howard. The " Registers of St. Antholin, Budge Row." had 

 previously been issued to subscribers by Messrs. Mitchell & Hughes. 

 The " Visitation of Gloucestershire in 1623," edited by Sir John 

 Maclean and W. C. Heane, Esq., will also be ready for members 

 this year; likewise Vol. I. of the " Registers of St. James, Clerken- 

 well," edited by Robert Hoveuden, Esq. 



XOTES ON FLYING AND FLYING- 

 MACHINES. 

 By RicH.iRD A. Proctor. 



(Continued from page 472.) 



TT/^E come next to a much more important point, namely, 

 V\ extent of supporting surface. We are to consider 

 the air now, not with regard to its density, the quality 

 which enables a balloon, filled with rarer gas, to float in 

 air, but with reference to its power of resisting downward 

 motion through it; that is, of resisting the effects of 

 gravity. We have to inquire what extent of surface, spread 

 either in the form of wings or as in parachutes, -n-ill sufiice 

 to support a man or a flying-machine. It is here that the 

 researches recently made seem to bear most significantly 

 upon the question of the possibility of flight. 



The history of the parachute afibrds some insight into 

 the supporting power of the air — some, but not much. 

 The parachute has been commonly [suffered to fall from 

 beneath the car of a balloon. .Suspended thus, in the lee, 

 so to speak, of the balloon's mass, and with its supporting 

 surface unexpanded, the parachute descends under highly 

 unfavourable conditions. A great velocity of descent is 

 acquired before the parachute is fully expanded, and thus 

 the parachute has to resist a greater down-drawing force 

 than would be the case if the machine were open, and 

 surrounded on all sides by free air, at starting. The conse- 

 quence is a great and sudden strain upon all parts of the 

 parachute, as well as a degree of oscillation which seriously 

 risks its structure, besides impairing its supporting power — 

 since this power would obviously act most effectively if the 

 span of the parachute remained horizontal throughout the 

 descent. The following account of Garnerin's descent, in 

 1797, illustrates the foregoing remarks : — " In 1797," says 

 Mr. Manley Hopkins, "Garnerin constructed a parachute, 

 by which he descended from a balloon, at an elevation of 

 2,000 feet. The descent was perilous, for the parachute 

 failed, for a time, to expand ; and after it had opened, and 

 the immediate fears of the immense concourse which had 

 assembled in Paris to witness the attempt had been removed, 

 the oscillations of the car, in which Garnerin was seated, 

 were so violent as to threaten either to throw him out, or, 

 on arriving at the gi-ound, to dash him out with violence. He 

 escaped, however ! " We notice the same circumstances 

 in the narrative of poor Cocking's disastrous attempt in 

 1837. "When the cords which sustained the parachute 

 were cut, it descended with dangerous rapidity, oscillating 

 fearfully, and at last the car broke away from the parachute, 

 and Mr. Cocking was precipitated to the ground, from a 

 height of about one hundred feet" 



But apart from these considerations, the parachute affords 

 no evidence whatever of the increased sustaining power of 

 the air on bodies which traverse it rapidly in a more or 

 less horizontal directioo. The parachute descends, and 

 descends quickly': we have to inquire whether the air may 

 not resist descent so strongly that with comparatively 

 small eftbrt a horizontal or even ascending motion may be 

 effected. 



A familiar illustration of this supporting power of the 

 atmosphere is given in the flight of an oyster-shell or piece 

 of thin slate, deftly thrown from a schoolboy's practised 

 hand. Such a missile, instead of following the parabolic 

 path traversed by an ordinary projectile, is seen to skim 

 along almost like a bird on resting piuions. It will some- 

 times even ascend (after the projectile force has ceased to 

 act in raising it), as though in utter disobedience to the 

 laws of gravitation. 



